Electric signaling system



Patented June 1, 1937 v r V g Y UNITED STATES PATENT OFFICE;

ELECTRIC SIGNALING SYSTEM Paul N. Bossart, Cheswick, Pa., assignor to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application August 14, 1936, Serial No. 96,008

12 Claims. (01.177-311) My invention relates to electric signaling syscludes a direct current magnet and governs a tems, and particularly to signaling systems for specific operation of the train brakes. Thus, in checking the integrity of electrical control cirone system of train brake control the operation cuits. of valve Vi opens the brake cylinder to the at- A feature of my invention is the provision of mosphere to release the brakes, the operation of 5 novel and improved apparatus to both check the valve V2 admits air pressure to the brake cyl continuity of the control wires of control cirinder to apply the brakes, while the valves V4, cults, and to detect short circuit conditions be- V5 and V6 are used in connection with a speed tween the control wires without interference governor to increase the brake cylinder pressure 10 to the operation of the apparatus governed by as the speed of the train is increased at certain 1') these control circuits. Other features and addefinite speeds. These electro-pneumatic valves vantages of my invention will appear as the are controlled through the medium of a con specification progresses. troller designated as a whole by the reference I will describe one form of apparatus embodycharacter 00, and which controller is ordinarily ing my invention, and will then point out the located at the head end of the train. This conl3 novel features thereof in claims. troller 0C includes five circuit controlling con.-,

The accompanying drawing is a diagrammatic tacts Si, S2, S3, S5 and St, which govern the conview of a preferred form of apparatus embodytrol circuits for the valves Vi, V2, V4, V5 and V6, in my invention when employed with an elecrespectively. Thus, with contact Si closed, a contro-pneumatic brake control system for railway trol circuit may be traced from one terminal of 20 trains. Although the invention is peculiarly a source of direct current such as battery 32 over fitted for employment with electro-pneumatic contact Si, choke coil Ll, control wire I, windbrake control systems for railway trains, its ing of electro -pn-eumatic valve Vi, common re.- utility is by no means to be limited to this one turn wire 3, and thence to the other terminal of 5 application as it is susceptible to use in other the current source, and the magnet of valve VI fields. It is to be understood that this one form is energized. It is to be understood, of course, of apparatus embodying the invention is by way that the corresponding electro-pneurnatic valve of illustrating the many places where it is useful. of each of the other cars of the train is ener Referring to the drawing, the control wires I, gized in parallel With valve VI. In a similar way,

2, 3, 4, 5, and 6 are the brake control wires of the closing of each of the other contacts S2, S4, 30

electro-pneumatic brake control system and S5 and S6 is effective to complete a control cirwhich wires each run the full length of the cult for energizing the corresponding valves V2, train. In the drawing the left-hand full line V4, V5 and Vii, as will be readily understood by portions of the control wires are at the forward an inspection of the drawing. The choke coils 35 end of the train, from which point the train Ll, L2, L4, L5 and LB are interposed one in each 35 brakes are controlled, the right-hand full line of the associated control circuits. The function portions of the control wires are at the rear of of these choke coils will be referred to later. It the train, the intermediate full line portions of is to be seen, therefore, that manipulation of the the control Wires are at an intermediate car of controller 00 to operate the several circuit conthe train, and the dotted line portions of the trolling contacts thereof is efiective to energize 40 control wires represent the portions through the and deenergize the several electro-pneumatic other cars of the train. The control wire 3 is a brake valves of the cars of the train. j common return wire which forms one side of The apparatus thus far described, except for each of five different control circuits, the other the choke coils, is that required for an electroside of each'of which is formed by a particular pneumatic train brake system in present day use. 5 one of the other wires I, 2, 4, 5, and 6. With such construction, it is desirable to check VI, V2, V4, V5 and V6 represent the electroand indicate the unbrokenness of the control pneumatic brake valves located on the abovewires and to also detect any short circuit between mentioned intermediate car of the train and any group of the control wires, so that the operthe windings of which valves are connected beator may be assured at all times that the train 50 tween the common return wire 3 and the other brake apparatus will function if operated. Acwires I, 2, 4, 5, and 6, respectively. It is to be cordingly, I provide signaling apparatus which is understood that a similar series of electro-pneueffective to check the unbrokenness of the con.- matic valves is located on each of the other cars trol wires and to detect any short circuit between of the train. Each of these valves, preferably, inany two of the wires, and to that end a source of 55 alternating current G, alternating current relays R2 and R4, condensers FCl, F02 and F05, fuses FFI, FFZ and FF5, indicator lamps GL and RL, direct current relay SR2 and a push button PB are located at the forward end of the train. At the rear end of the train there are located alternating current relays RI, R3 and R5, condensers RC2, RC4 and RC5, fuses RFZ, RF4 and RF6, and a direct current relay SRi.

This signaling apparatus is arranged to connect the several control wires I, 2, 3, 4, 5, and 5 in a series signaling circuit which extends back and forth from the front to the rear end of the train. Starting with the top terminal of generator G this series signaling circuit may be traced over condenser FCl, fuse FFl, control wire I to the rear end of the train, wire 7, front contact 8 of relay R5, wire 9, winding of relay Rl, fuse RFZ, condenser RC2, control wire 2 to the front end of the train, condenser FC2, fuse FFZ, winding of relay R2, control wire 3 to the rear end of the train, front contact H] of relay RI, winding of relay R3, fuse RF4, condenser RC4, control wire 4 to the front end of the train, front contact H of relay R2, winding of relay R4, fuse FF5, condenser FC5, control wire 5 to the rear end of the train, front contact I2 of relay RS, winding of relay R5, fuse RFS, condenser RC6, control wire 5 to the front end of the train, front contact I 3 of relay Rd, indicator lamp GL, and thence to the opposite terminal of the generator G. It follows that alternating current flows through this series circuit from generator G to illuminate lamp GL providing the relays R5 R2, R3, R and R5 are all picked up and the con trol wires 2, 3, 4 5, and 6 are unbroken, but if any one of the control wires breaks or a relay is deenergized the circuit is opened, the relays are all released and the lamp GL is extinguished. With relay R4 released and its back contact l4 closed, a simple circuit is completed for supplying current from any convenient source of current, not shown, to the indicator lamp RL andv that lamp is illuminated to warn the operator of trouble in the series signaling circuit.

Any short circuit between two or more of the control wires will deenergize one or more of the relays Rl, R2, R5, R4 and R5, which in turn will release and open the series circuit at some point not included in the short circuit. This characteristic of the series circuit is assured by the fact that the winding of an alternating current relay is interposed in each connection where two control wires are connected together and a front contact of each relay is interposed in the adjacent connection of the control wires, while the source of current is connected between the first and the last of the control wires. Thus, the operating winding of relay R! is interposed in the connection between the control wires i and 2 and the front contact IQ of relay R! is interposed in the next adjacent connection be tween control wires 3 and 4, the operating winding of relay R2 is interposed in the connection between control wires 2 and 3 and front contact ll of relay R2 is interposed in the adjacent connection between control wires 4 and 5, the operating winding of relay R3 is interposed in the connection between control wires 3 and 4 and its front contact I2 is interposed in the adjacent connection between wires 5 and 5, the operating winding of relay R4 is interposed in the connection between control wires 5 and 5' and its front contact I3 is interposed in the adjacent circuit with two front contacts l8 and 19.

connection leading from control wire 5 to the generator G, and the operating winding of relay R5 is interposed in the connection between control wires 5 and 5 and its front contact 8 is interposed in the adjacent connection between control wires I and 2. A short circuit between control wires l and 2 shunts relay RI and that relay releases to open the series circuit at front contact [I] which is external to the short circuit between Wires I and 2. A short circuit between wires 5 and 3 shunts both relays R! and R2 and the series circuit is opened at front contacts ill and H. A study of this series circuit will disclose that a short circuit between any two or more of the control wires will shunt at least one of the relays and open the series circuit at a contact external to the short circuit and thus deenergize all of the relays and warn the operator of the trouble.

The condensers FCI, FC2 and F05 at the forward end of the train and the condensers RC2, RC4 and RC5 at the rear end of the train are provided to block the flow of direct current in the series circuit but allow the alternating current to flow. In case trouble should occur, such as a short circuit in condensers FCZ, there would be a low resistance path for direct current from control wire 2 through condenser F02 short circuited, fuse FFZ, and winding of relay R2 to control wire 3, since the ohmic resistance of the winding of relay R2 would be low. FF2 associated with condenser FCZ is so chosen as to melt when a current slightly larger than the maximum current required for the series circuit is passed therethrough. Hence, in the case condenser is short circuited and contact S2 is closed and the battery 32 is connected across control wires 2 and 3, the fuse FF2 would melt in response to the direct current passing through alternating current G, the fuse FF! protecting against a short circuit condition of condenser FCI the same way as fuse FFZ protects against a short circuit condition of condenser FCZ. The choke coils Ll, L2, L l, L5 and L5 are used to offer a high impedance to the alternating cur rent through the source of direct current 32.

When power is first applied to the series circuit it is necessary to bridge around the front contacts of the several alternating current relays in order to initially energize the operating windings of these relays and pick up the relays to close the series circuit, This is accomplished by means of the direct current relays SR! and SR2. Relay SR5 is provided with three front contacts l5, l6

and il. Front contact I5, when closed, completes a shunt path around front contact I!) of relay Rt, front contact l5 completes a shunt path around front contact 12 of relay R3, and front contact I? completes a shunt path around front contact 8 of relay R5. Relay SR2 is provided Front contact l8, when closed, completes a shunt path around front contact H of relay R2, and front contact lSlcompletes a shuntpath around front contact 13 of relay R4.

The fuse Remy SRI is energized with direct current when contact SI is initially closed to connect the battery 32 across the control wires I and 3. This circuit for relay SRI may be traced from battery 32, over contact SI, choke coil LI, control wire I, winding of relay SRI, back contact 20 of relay RI and common return wire 3 back to battery 32. When contact SI is closed the relay SR2 is energized by depressing the push button PB to close its contact 2I-22, as will be readily understood by an inspection of the drawing. It

will be seen, therefore, that when contact SI and push button PB are operated the two relays SRI and SR2 are picked up and the series circuit is completed, with the result that all of the relays RI, R2, R3, R4 and R5 are energized and picked up to close their respective front contacts. When relay RI picks up and opens its back contact 20, the relay SRI is deenergized and releases to open the shunt paths around the front contacts of relays RI, R3 and R5. With push button PB released, the relay SR2 is deenergized and releases to open the shunt paths around the front contacts of relays R2 and R4. In order to make sure that the alternating current relays are picked up the contact SI may be opened momentarily to remove energy from the relays SRI and SR2 and deenergize these relays. In case some trouble prevents the alternating current relays from picking up, the lamp GL will be extinguished when relays SRI and SR2 are released and the lamp RL will remain illuminated to indicate the trouble. The train brake control system referred to hereinbefore has provision for operating pneumatically alone and the operator would be expected to switch over to this mode of operation when any trouble is indicated by the lamps GL and RL, either during normal operation or in the case of failure to initially energize the series circuit.

Although the electro-pneumatic valves are op erated on direct currentand their magnets are each wound with a relatively large number of turns, they still may have a relatively low impedance for 60 cycle alternating current, which is the frequency of the alternating current usually available, since the magnets of the several valves form shunt paths for the series circuit and since each car of the train is provided with a series .of the valves.

certain relays of the series circuit might be energized with current of a magnitude much larger than the magnitude of the current energizing other relays of the series circuit. The choke coils LI, L2, etc., also exert a shunt effect on the series circuit when the corresponding controller contacts are closed. It can be shown that the impedance of the relay condenser combination which bridges two control wires should be not more than one-third as great as that of the lowest shunt which might be placed across these two control wires by the apparatus of the brake control system. The alternating current relays are preferably selected so that the impedance of the associated condenser is largely balanced out by the inductive reactance of the relay. Furthermore, the relays RI, R2,'etc., are preferably designed to have about the same impedance in the open position as in the closed position. In considering the commercial adaptation of the invention to a brake control system of the type referred to hereinbefore, commercial condensers of about 500 microfarads and alternating current relays of a standard Z armature type will provide a series circuit which will function efficiently and the cost of which will be reasonable.

Although the series signaling circuit is here employed with six control wires it may be used with a less or a greater number of control wires. For example, if only four control wires are to be checked, the relays R4 and R5 would be omitted. In this case, relay R3 would control the connection between wires I and 2 and which connection includes the winding of relay RI, and relay R2 would control the connection between wire 4 and the source of alternating current. If eight control wires are to be checked then an additional alternating current relay would be located both at the front and rear ends of the train and these additional relays would be inserted in the circuit in a manner similar to relays RI to R5. It should be pointed out that the signaling circuit embodying my invention may be used with any even number of control wires greater than two, and may be readily applied to any odd number of control wires greater than one if a return wire is provided, either one used already for another purpose, or one added to complete the signaling circuit.

Although'I have herein shown and described only one form of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what'I claim is:

1. In a control system involving at least four control wires each extending between two remote stations the combination therewith including, a source of current at one station and having itsterminals connected between a first and a last one of the control wires, a plurality of relays part located at said one station and part located at the other station, means to connect the control wires in a series circuit back and forth from one station to the other with a winding of a different one of the relays interposed in each connection where two control wires are connected together and with a front contact of each relay interposed in the next adjacent connection of the control wires, and signaling means responsive to current flowing in said series circuit.

2. In a control system involving at least four control wires each extending between two remote stations the combination therewith including, a source of current at one station and having its terminals connected between a first and a last one of the control wires, a plurality of relays part located at said one station and part located at the other station, means to connect the control wires in a series circuit back and forth from one station to the other with a winding of a different one of the relays interposedin each connection where two control wires are connected together and with a front contact of each relay interposed in the next adjacent connection of the control wires, means partly at each of said stations to at times shunt around the front contact of each of the relays toinitially energize said series circuit, and signaling means controlled by said series circuit.

3. In a control system involving at least four control wires each extending between two remote stations the combination therewith including, a source of current at one station and having its terminals connected between a first and a last one of the control wires, a plurality of relays part located at said one station and part located at the other station, means to connect the control wires in a series circuit back and forth from one station to the other with a winding of a different one of the relays interposed in each connection where two control wires are connected together and with a front contact of each relay interposed in the next adjacent connection of the control wires, whereby a short circuit between any group of the control wires deenergizes a relay to open a contact external to the short circuit which will cause all the relays to be deenergized, and signaling means controlled by at least one of the relays.

4. In a control system involving at least four control wires each extending between two remote stations the combination therewith including, a source of current at one station and having its terminals connected between a first and a last one of the control wires, a plurality of relays part located at said one station and part located at the other station, means to connect the control wires in a series circuit back and forth from one station to the other with a winding of a different one of the relays interposed in each connection where two control wires are connected together and with a front contact of each relay interposed in the next adjacent connection of the control wires, whereby a break in a control wire or a short circuit between any two of the control wires will cause the series circuit to be opened and all the relays cleenergized, a first signaling means responsive to current flowing in said circuit, and a second signaling means controlled over a back contact of at least one of said relays.

5. In a control system involving at least three control wires each extending'between two remote stations the combination therewithincluding, a source of signaling current, a plurality of relays responsive to such signaling current, means to connect the control wires in a series circuit starting from one terminal of the source of current and passing back and forth from one station to the other over the control wires with the winding of a different one of the relays interposed in each connection where two control wires are connected together and with the remote end of the last control wire connected with the other terminal of the current source and with a front contact of each relay interposed in the next adjacent connection, and signaling means responsive to the current fiowing in said series circuit.

6 In a direct current control system involving at least four control wires each extending between two remote stations the combination therewith including, a source of alternating current at one station and having its terminals connected between a first and a last one of the control wires, a plurality of alternating current relays, means to connect the control wires in a series circuit back and forth from one station to the other with a winding of a different one of said relays interposed in each connection where two control wires are connected together and with a front contact of each relay interposed in the next adjacent connection of the control wires, a direct current relay at each station and having front contacts which shunt around the front contacts of the alternating current relays at the same station, manually controlled means for at times energizing said direct current relays to close the series circuit to initially energize the alternating current relays whereby said series circuit is then effective to check the unbrokenness of the control wires and to detect a short circuit between any group of the control wires, and signaling means governed by said series circuit.

7 In a direct current control system involving at least four control wires each extending between two remote stations the combination therewith including, a source of alternating current at one station and having its terminals connected between a first and a last one of the control wires, a plurality of alternating current relays, a plurality of condensers, a plurality of fuses, means to connect the control wires in a series circuit back and forth from one station to the other with a winding of a relay together with a condenser and a fuse interposed in the connection where two control wires are connected together and with a front contact of each relay interposed in the next adjacent connection of the control wires, a direct current relay at each station having front contacts which shunt around the front contacts of the alternating current relays at the same station, manually controlled means for at times energizing said direct current relays to initially energize the alternating current relays whereby said series circuit is closed and is effective to check the unbrokenness of the control wires and to detect a short circuit between any group of the control wires without interference from said control system and to detect a short circuit condition of a condenser.

8. In a signal system involving six control wires extending from a control station to a remote station, a first relay at the remote station and having an operating winding connected between a first and a second of the control wires, a second relay at the control station and having an operating winding connected between the second and a third of the control wires, a third relay at the remote station and having an operating winding connected between the third and a fourth of the control wires, a fourth relay at the control station and having an operating winding connected between the fourth and a fifth of the control wires, a fifth relay at the remote station and having an operating winding connected between the fifth and a sixth of the control wires, a source of current at the control station connected between the first and sixth control wires, a front contact of the first relay interposed in the winding connection of the third relay, a front contact of the second relay interposed in the winding connection of the fourth relay, afront contact of the third relay interposed in the winding connection of the fifth relay, a front contact of the fourth relay interposed in the connection to the current source, a front contact of the fifth relay interposed in the winding connection of the first relay, means for at times shunting around each of said front contacts for initially energizing said relays, and an indicator interposed in the connection to the current source.

9. In a signal system involving six control wires extending between a control station and a remote station, five relays the first, third and fifth of which are located at the remote station and the second and fourth of which are located at the control station, means including a front contact of the fifth relay to connect a winding of the first relay between a first and a second of the control wires, means including a front contact of the first relay to-connect a winding of the third relay between a third and a fourth of the control wires, means including a front contact of the third relay to connect a winding of the fifth relay between a fifth and a sixth of the control wires, means to connect a winding of the second relay between the second and third control wires, means including a front Contact of the second relay to connect a winding of the fourth relay between the fourth and fifth control wires, a current source, means including a front contact of the fourth relay to connect said source between the first and sixth control wires, means for at times shunting around the front contact of each of said relays to initially energize said relays whereby said control wires are serially supplied with current from said source, and signaling means governed by the current flowing in said control wires.

10. In a signal system involving at least four control wires extending between a control station and a remote station, three relays a first and a third of which are located at the remote station and a second of which is located at the control station, means including a front contact of the third relay to connect a winding of the first relay between a first and a second of the control wires, means including a front contact of the first relay to connect a winding of the third relay between a third and a fourth of the control Wires, means to connect a winding of the second relay between said second and third control wires, a current source, means including a front contact of the second relay to connect said source between the first and fourth control wires, means for at times shunting around the front contact of each of said relays to initially energize the relays whereby said control wires are serially supplied with current from said source, and signaling means governed by the current flowing in said control wires.

11. In a signal system involving at least three control wires extending between a control station and a remote station, three relays a first and a third of which are located at the remote station and a second of which is located at the control station, means including a front contact of the third relay to connect a winding of the first relay between a first and a second one of the control wires, means to connect a winding of the second relay between the second and a third one of the control wires, a current source located at the control station, means to connect one terminal of the source with said first control Wire, means including a front contact of said first relay and a front contact of said second relay to connect a winding of the third relay between said third control wire and the other terminal of the current source, means for at times shunting around the front contact of each of said relays to initially energize said relays whereby said control wires are serially supplied with current from said source, and signaling means responsive to the current flowing in said control wires.

12. In a signal system involving at least four control wires extending between a control station and a remote station, three relays a first and a third of which are located at the remote station and a second of which is located at the control station, means including a front contact of the third relay to connect a winding of the first relay between a first and a second of the control wires, means including a front contact of the first relay to connect a Winding of the third relay between a third and a fourth of the control wires, means to connect a winding of the second relay between said second and third control wires, a current source, means including a front contact of the second relay to connect said source b tween the first and fourth control wires, a fourth relay located at the remote station and having front contacts which shunt around the front contacts of said first and third relays, a fifth relay located at the control station and having a front contact which shunts around the front contact of said second relay, means including a back contact of the first relay and a push button at the control station to energize said fourth and fifth relays for initially energizing said first and third relays as well as the second relay whereby said control wires are serially supplied with current from said source, and signaling means responsive to the current flowing in said control wires.

PAUL N. BOSSART. 

